A bag contains 7 red and 10 white balls. In how many ways 4 balls are selected if there are more than 2 red balls? (Please solve
1 answer:
Answer:
385 ways
Step-by-step explanation:
Given;
7 red balls
10 white balls
In how many ways can 4 balls be selected if there are more than 2 red balls.
Selecting 4 balls which must contain more than 2 red balls, will be 3 red balls and 1 white ball to make it 4 in total, or all the 4 balls selected will red balls.
= 3 red balls and 1 white ball OR 4 red balls
= 7C₃ x 10C₁ + 7C₄
Therefore, there are 385 ways of selecting 4 balls, if there are more than 2 red balls.
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- ∠RSU and ∠USV are complementary angles
- ∠RSU = (4x – 15)°
- ∠USV = 20°
- The value of x
- ∠RSU and ∠USV are complementary angles
Given:
To find:
The obtuse angle between the given pair of straight lines.
Solution:
The slope intercept form of a line is
...(i)
where, m is slope and b is y-intercept.
The given equations are
On comparing these equations with (i), we get
Angle between two lines whose slopes are is
Putting and
, we get
Now,
and
and
and
, so it is an obtuse angle and
, so it is an acute angle.
Therefore, the obtuse angle between the given pair of straight lines is 120°.